Power-grid-impact-free detection method for low voltage ride through function of doubly-fed wind turbine generator system

Abstract

A power-grid-impact-free detection method for the low voltage ride through function of a doubly-fed wind turbine generator system is characterized in that the stator side of the doubly-fed wind turbine generator system and a power grid are in the off state all the time when the low voltage ride through function of the doubly-fed wind turbine generator system is detected through the detection method, power grid faults of different types and different voltage drop depths are simulated by inputting a reactor with the adjustable resistance value, and the output waveforms of a converter of the doubly-fed wind turbine generator system and all physical quantities of an electric generator are detected so that whether the doubly-fed wind turbine generator system has the low voltage ride through function meeting the requirement of the national standard or not can be judged. By means of the detection method, whether the doubly-fed wind turbine generator system has the low voltage ride through function or not can be effectively verified, the performance index of the low voltage ride through of the doubly-fed wind turbine generator system can be rapidly obtained, no impact on the power grid is caused in the detection process, the detection method is simple and feasible, the detection result is visual and accurate, the detection cost is low, and the detection method is particularly suitable for the field of the wind power plant online detection of the low voltage ride through function of the doubly-fed wind turbine generator system.

Description

technical field [0001] The invention relates to a detection method for the low-voltage ride-through function of a wind turbine, in particular to a detection method for the low-voltage ride-through function of a doubly-fed wind turbine without grid impact. Background technique [0002] With the rapid increase of wind power installed capacity, the interaction between wind turbines and the grid has become increasingly prominent. Since the stator side of the doubly-fed wind turbine is directly connected to the grid, compared with other wind turbine models, its low-voltage ride-through capability is poor. . When a short-circuit fault occurs in the power grid, the stator voltage of the doubly-fed generator will also change suddenly, and the stator flux of the generator will contain transient DC components, positive sequence and negative sequence components, and the joint action of these flux components will cause generator Rotor overvoltage and overcurrent. In this case, if the ...

AI Technical Summary

Problems solved by technology

The key to realizing the detection of the low voltage ride-through function of wind turbines is to simulate the occurrence and elimination of various grid faults, so that the wind turbines can sense various grid faults. However, the existing technology needs to use a large number of reactor devices for simulating short-circuit faults in the grid. And the detection process will also cause an impact on the power grid

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